iMovie '08 Library Compressor for Mac

From Nik's Software:

Movie '08 Library Compressor is a simple program to reduce the size of your iMovie '08 library. This application will compress all the DV files in your iMovie library to save huge amounts of disk space! Using H.264 compression, you can shave as much as 93% of the space of your raw DV files! This is a simple applet, just double click it, select your chosen compression settings (from a pristine copy that shaves off 10% of the file size to a clip that's 93% smaller than the original, and only suitable for posting on YouTube), and let it work its magic. Your library will sweat off the pounds, and your original raw DV files will be set aside to be archived, thrown away, or whatever you want to do with them. Free and open source.